catena-Poly[[[diaqua­copper(II)]-bis­[μ-1,5-bis­(1H-imidazol-1-yl)pentane-κ²N³:N^3′]] naphthalene-1,5-disulfonate]

In the title complex, {[Cu(C₁₁H₁₆N₄)₂(H₂O)₂](C₁₀H₆O₆S₂)}_n, the Cu^II atom, lying on an inversion center, is six-coordinated by two water mol­ecules and four N atoms from four 1,5-bis­(1H-imidazol-1-yl)pentane (biim-5) ligands in a distorted octa­hedral geometry. Adjacent Cu^II atoms are linked by two biim-5 ligands, forming a chain along [111]. Two atoms of the pentane group are disordered over two sets of sites, with an occupancy ratio of 0.554 (18):0.446 (18). Inter­molecular O—H...O hydrogen bonds link the chains and the centrosymmetric naphthalene-1,5-disulfonate anions into a layer structure parallel to (0-11).